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1/*
2 * include/linux/cpu.h - generic cpu definition
3 *
4 * This is mainly for topological representation. We define the
5 * basic 'struct cpu' here, which can be embedded in per-arch
6 * definitions of processors.
7 *
8 * Basic handling of the devices is done in drivers/base/cpu.c
9 *
10 * CPUs are exported via sysfs in the devices/system/cpu
11 * directory.
12 */
13#ifndef _LINUX_CPU_H_
14#define _LINUX_CPU_H_
15
16#include <linux/node.h>
17#include <linux/compiler.h>
18#include <linux/cpumask.h>
19
20struct device;
21
22struct cpu {
23 int node_id; /* The node which contains the CPU */
24 int hotpluggable; /* creates sysfs control file if hotpluggable */
25 struct device dev;
26};
27
28extern int register_cpu(struct cpu *cpu, int num);
29extern struct device *get_cpu_device(unsigned cpu);
30extern bool cpu_is_hotpluggable(unsigned cpu);
31extern bool arch_match_cpu_phys_id(int cpu, u64 phys_id);
32
33extern int cpu_add_dev_attr(struct device_attribute *attr);
34extern void cpu_remove_dev_attr(struct device_attribute *attr);
35
36extern int cpu_add_dev_attr_group(struct attribute_group *attrs);
37extern void cpu_remove_dev_attr_group(struct attribute_group *attrs);
38
39#ifdef CONFIG_HOTPLUG_CPU
40extern void unregister_cpu(struct cpu *cpu);
41extern ssize_t arch_cpu_probe(const char *, size_t);
42extern ssize_t arch_cpu_release(const char *, size_t);
43#endif
44struct notifier_block;
45
46#ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
47extern int arch_cpu_uevent(struct device *dev, struct kobj_uevent_env *env);
48extern ssize_t arch_print_cpu_modalias(struct device *dev,
49 struct device_attribute *attr,
50 char *bufptr);
51#endif
52
53/*
54 * CPU notifier priorities.
55 */
56enum {
57 /*
58 * SCHED_ACTIVE marks a cpu which is coming up active during
59 * CPU_ONLINE and CPU_DOWN_FAILED and must be the first
60 * notifier. CPUSET_ACTIVE adjusts cpuset according to
61 * cpu_active mask right after SCHED_ACTIVE. During
62 * CPU_DOWN_PREPARE, SCHED_INACTIVE and CPUSET_INACTIVE are
63 * ordered in the similar way.
64 *
65 * This ordering guarantees consistent cpu_active mask and
66 * migration behavior to all cpu notifiers.
67 */
68 CPU_PRI_SCHED_ACTIVE = INT_MAX,
69 CPU_PRI_CPUSET_ACTIVE = INT_MAX - 1,
70 CPU_PRI_SCHED_INACTIVE = INT_MIN + 1,
71 CPU_PRI_CPUSET_INACTIVE = INT_MIN,
72
73 /* migration should happen before other stuff but after perf */
74 CPU_PRI_PERF = 20,
75 CPU_PRI_MIGRATION = 10,
76 /* bring up workqueues before normal notifiers and down after */
77 CPU_PRI_WORKQUEUE_UP = 5,
78 CPU_PRI_WORKQUEUE_DOWN = -5,
79};
80
81#define CPU_ONLINE 0x0002 /* CPU (unsigned)v is up */
82#define CPU_UP_PREPARE 0x0003 /* CPU (unsigned)v coming up */
83#define CPU_UP_CANCELED 0x0004 /* CPU (unsigned)v NOT coming up */
84#define CPU_DOWN_PREPARE 0x0005 /* CPU (unsigned)v going down */
85#define CPU_DOWN_FAILED 0x0006 /* CPU (unsigned)v NOT going down */
86#define CPU_DEAD 0x0007 /* CPU (unsigned)v dead */
87#define CPU_DYING 0x0008 /* CPU (unsigned)v not running any task,
88 * not handling interrupts, soon dead.
89 * Called on the dying cpu, interrupts
90 * are already disabled. Must not
91 * sleep, must not fail */
92#define CPU_POST_DEAD 0x0009 /* CPU (unsigned)v dead, cpu_hotplug
93 * lock is dropped */
94#define CPU_STARTING 0x000A /* CPU (unsigned)v soon running.
95 * Called on the new cpu, just before
96 * enabling interrupts. Must not sleep,
97 * must not fail */
98
99/* Used for CPU hotplug events occurring while tasks are frozen due to a suspend
100 * operation in progress
101 */
102#define CPU_TASKS_FROZEN 0x0010
103
104#define CPU_ONLINE_FROZEN (CPU_ONLINE | CPU_TASKS_FROZEN)
105#define CPU_UP_PREPARE_FROZEN (CPU_UP_PREPARE | CPU_TASKS_FROZEN)
106#define CPU_UP_CANCELED_FROZEN (CPU_UP_CANCELED | CPU_TASKS_FROZEN)
107#define CPU_DOWN_PREPARE_FROZEN (CPU_DOWN_PREPARE | CPU_TASKS_FROZEN)
108#define CPU_DOWN_FAILED_FROZEN (CPU_DOWN_FAILED | CPU_TASKS_FROZEN)
109#define CPU_DEAD_FROZEN (CPU_DEAD | CPU_TASKS_FROZEN)
110#define CPU_DYING_FROZEN (CPU_DYING | CPU_TASKS_FROZEN)
111#define CPU_STARTING_FROZEN (CPU_STARTING | CPU_TASKS_FROZEN)
112
113
114#ifdef CONFIG_SMP
115/* Need to know about CPUs going up/down? */
116#if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE)
117#define cpu_notifier(fn, pri) { \
118 static struct notifier_block fn##_nb = \
119 { .notifier_call = fn, .priority = pri }; \
120 register_cpu_notifier(&fn##_nb); \
121}
122#else /* #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
123#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
124#endif /* #else #if defined(CONFIG_HOTPLUG_CPU) || !defined(MODULE) */
125#ifdef CONFIG_HOTPLUG_CPU
126extern int register_cpu_notifier(struct notifier_block *nb);
127extern void unregister_cpu_notifier(struct notifier_block *nb);
128#else
129
130#ifndef MODULE
131extern int register_cpu_notifier(struct notifier_block *nb);
132#else
133static inline int register_cpu_notifier(struct notifier_block *nb)
134{
135 return 0;
136}
137#endif
138
139static inline void unregister_cpu_notifier(struct notifier_block *nb)
140{
141}
142#endif
143
144int cpu_up(unsigned int cpu);
145void notify_cpu_starting(unsigned int cpu);
146extern void cpu_maps_update_begin(void);
147extern void cpu_maps_update_done(void);
148
149#else /* CONFIG_SMP */
150
151#define cpu_notifier(fn, pri) do { (void)(fn); } while (0)
152
153static inline int register_cpu_notifier(struct notifier_block *nb)
154{
155 return 0;
156}
157
158static inline void unregister_cpu_notifier(struct notifier_block *nb)
159{
160}
161
162static inline void cpu_maps_update_begin(void)
163{
164}
165
166static inline void cpu_maps_update_done(void)
167{
168}
169
170#endif /* CONFIG_SMP */
171extern struct bus_type cpu_subsys;
172
173#ifdef CONFIG_HOTPLUG_CPU
174/* Stop CPUs going up and down. */
175
176extern void cpu_hotplug_begin(void);
177extern void cpu_hotplug_done(void);
178extern void get_online_cpus(void);
179extern void put_online_cpus(void);
180extern void cpu_hotplug_disable(void);
181extern void cpu_hotplug_enable(void);
182#define hotcpu_notifier(fn, pri) cpu_notifier(fn, pri)
183#define register_hotcpu_notifier(nb) register_cpu_notifier(nb)
184#define unregister_hotcpu_notifier(nb) unregister_cpu_notifier(nb)
185void clear_tasks_mm_cpumask(int cpu);
186int cpu_down(unsigned int cpu);
187
188#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
189extern void cpu_hotplug_driver_lock(void);
190extern void cpu_hotplug_driver_unlock(void);
191#else
192static inline void cpu_hotplug_driver_lock(void)
193{
194}
195
196static inline void cpu_hotplug_driver_unlock(void)
197{
198}
199#endif
200
201#else /* CONFIG_HOTPLUG_CPU */
202
203static inline void cpu_hotplug_begin(void) {}
204static inline void cpu_hotplug_done(void) {}
205#define get_online_cpus() do { } while (0)
206#define put_online_cpus() do { } while (0)
207#define cpu_hotplug_disable() do { } while (0)
208#define cpu_hotplug_enable() do { } while (0)
209#define hotcpu_notifier(fn, pri) do { (void)(fn); } while (0)
210/* These aren't inline functions due to a GCC bug. */
211#define register_hotcpu_notifier(nb) ({ (void)(nb); 0; })
212#define unregister_hotcpu_notifier(nb) ({ (void)(nb); })
213#endif /* CONFIG_HOTPLUG_CPU */
214
215#ifdef CONFIG_PM_SLEEP_SMP
216extern int disable_nonboot_cpus(void);
217extern void enable_nonboot_cpus(void);
218#else /* !CONFIG_PM_SLEEP_SMP */
219static inline int disable_nonboot_cpus(void) { return 0; }
220static inline void enable_nonboot_cpus(void) {}
221#endif /* !CONFIG_PM_SLEEP_SMP */
222
223enum cpuhp_state {
224 CPUHP_OFFLINE,
225 CPUHP_ONLINE,
226};
227
228void cpu_startup_entry(enum cpuhp_state state);
229void cpu_idle(void);
230
231void cpu_idle_poll_ctrl(bool enable);
232
233void arch_cpu_idle(void);
234void arch_cpu_idle_prepare(void);
235void arch_cpu_idle_enter(void);
236void arch_cpu_idle_exit(void);
237void arch_cpu_idle_dead(void);
238
239#endif /* _LINUX_CPU_H_ */